Not ever; not at any time; at no time, whether past, present, or future.
In no degree; not at all; not a whit; not, emphatically.
[Never in this use, with the following indefinite article a, is equivalent to no, or none, and in the contracted form ne'er a is the source of the dialectal or slang adjectivc nary.
[In this idiom there is a suppressed comparison—‘never (at any other time) so (great, good, much, etc.) as in the case supposed or considered.’ Never, becoming merely emphatic, is now usually replaced by ever.